This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. During cell division, chromatin remodeling (local and global structural changes in chromatin) is necessary for both transcription and chromosomal segregation. In eukaryotes, ATP-dependent chromatin remodeling is performed by large multi-protein assemblies that modulate DNA-nucleosome interactions. We are working to refine structural models of the multi-protein RSC (Remodels the Structure of Chromatin) complex in yeast (Saccharomyces cerevisiae), an ATP-dependent chromatin remodeler with homologous counterparts in humans and higher eukaryotes.